Watches can prevent our phone being stolen! I have noticed that many younger people are using their mobile phones to tell the time. This is bad news as it makes it possible to snatch the phone while they are distracted. Keep it out of sight.
3) A watch will continue to work when a phone will not. They do not need to be recharged and are often water and shock resistant.
My own watch is titanium (very light and strong) and solar powered as well as being moderately waterproof. If it prevents the theft of my iPhone then it is an investment indeed.